Counterfeiting of goods is a major concern for corporate, federal and state organizations. Counterfeits can compromise the security, identity and value of products, documents, identifications, and currency, thereby exerting a strong negative impact on societal, financial and social wellbeing.
Of particular concern is document and image security. By their very nature, documents are susceptible to alteration and forgery. In particular, visual indicia printed on the document to establish the authenticity of the same may be modified or deleted by a malfeasant. In other instances, the details of and/or information contained within the document may be improperly altered to benefit a wrongdoer at the expense of another. Therefore, a need exists in the art to provide invisible taggants that can be read by a device to verify the authenticity of and/or information contained with a document. For example, artwork would benefit from having an associated taggant that is concealed and/or imperceptible to the naked eye, but readable by a device.
Of another particular concern is supply chain security and pharmaceutical packaging. An important component of supply chain security is screening and validating of the contents of cargo being shipped. Doing so often involves scanning and comparing barcodes, two-dimensional codes and/or radiofrequency identification (RFID) tags. Similarly, manufacturers and distributors of pharmaceuticals are increasingly investing in countermeasures, such as traceability and authentication technologies, to minimize the impact of counterfeit medicines deliberately mislabeled to deceive consumers. A savvy counterfeiter, however, may become privy to the location and properties of the identifiers of genuine packaging, products and/or pharmaceuticals and forge those as well. In order to reduce the cases of counterfeiting across supply chain management, pharmaceutical packing, and numerous additional industries, a need exists in the art for a scanning device capable of verifying critical product information encoded on covert and/or invisible taggants applied to packaging and/or products for authentication.
Of yet another particular concern is counterfeiting integrated circuits because of its potential to compromise the performance of a wide range of critical infrastructure ranging from healthcare devices to military equipment to space hardware. The counterfeit integrated circuits are often fraudulent or degraded products that have been either rejected during the quality control or recycled from waste. In operation, the counterfeiting of integrated circuits often involves removing a label of a casing by sanding, reprinting the label of a more expensive item, then selling it back to the manufacturer and/or a distributor for a profit.
The markings within the integrated circuit packaging can make tampering a difficult task without damaging the component itself or the electronic packaging. Integrated circuits are often enclosed in an epoxy case (or mold compound) and electronic circuit boards are frequently coated with polymer films. Epoxy is very chemically resistant and is insoluble in common solvents, making it difficult to remove in order to reach the embedded code. A system of markings coated below an opaque epoxy layer would be difficult to detect and quite tamper resistant. Therefore, a further need exists in the art to provide a device that can read and decode printed features through opaque, hard polymer or epoxy coatings.
Upconversion phosphors emit light at wavelengths shorter than that of the excitation light. The concentration and combination of lanthanide dopants influence both the wavelength and the intensity of the upconversion emission. The inks are a formulation of upconversion nanoparticles (UCNPs) dispersed in a polymer base. When used to print text or features (e.g., quick response (QR) codes) on paper, the upconversion ink is invisible to the eye under ambient conditions or ultraviolet excitation, but becomes visible upon excitation with NIR light. In particular, lanthanide-ion-doped β-NaYF4 is recognized for exceptionally efficient visible upconversion upon excitation with NIR light with a wavelength of approximately 980 nanometers (nm). An exemplary system and method for creating NIR upconverting inks is disclosed by U.S. Pub. No. 2014/0261031 to Kellar et al., which is herein incorporated in its entirety.
β-NaYF4 UCNPs doped with Yb3+ and Tm3+ are known for NIR-to-blue upconversion emission between wavelengths of 440 and 500 nm. These blue UCNP inks, however, also emit NIR light at a wavelength of 800 nm, which is invisible to the naked eye, but much more intense than the visible blue emission. Moreover, these coatings can be completely opaque as long as the coating transmits both 800 nm and 980 nm wavelengths. Therefore, a further need exists in the art to capture of NIR images of UCNP inks coated with NIR transparent materials that are opaque in the visible range.